The telephone survey of 2,001 California adults, including 1,047 likely voters, reveals that Proposition 8 — the proposed constitutional amendment to bar same-sex couples from marrying — is losing badly. Among likely voters, only 40% plan to vote for the amendment, compared to 54% who say they will vote against it. The remaining 6% are undecided. (The margin of error is +/- 3 percent.)

The PPIC data are identical to those obtained in a May Field Poll, which found the same 54-40% split in response to the question, “Do you favor or oppose changing the California State Constitution to define marriage as between a man and a woman, thus barring marriage between gay and lesbian couples?” (In the same Field Poll, a differently-worded question also elicited majority opposition to a constitutional amendment, 51-43%.)

In the new survey, PPIC interviewers essentially read the ballot description to each respondent before asking their voting intentions:

“Proposition 8 is called the ‘Eliminates Right of Same-Sex Couples to Marry Initiative Constitutional Amendment.’ It changes the California Constitution to eliminate the right of same-sex couples to marry. It provides that only marriage between a man and a woman is valid or recognized in California. Fiscal impact over the next few years includes potential revenue loss, mainly sales taxes, totaling in the several tens of millions of dollars, to state and local governments. In the long run, it will likely have little fiscal impact on state and local governments. If the election were held today, would you vote yes or no on Proposition 8?

Thus, the new poll gave respondents the same information they’ll receive when they cast their ballot.

Who Supports and Opposes Proposition 8?

The PPIC hasn’t yet released detailed breakdowns of responses to the Prop. 8 question, which was part of a lengthy survey about candidates and issues related to the November election. However, their press release and report highlighted some key patterns:

Consistent with previous polls, geography and political ideology are important predictors of support for Prop. 8. Among likely voters, the amendment is favored by Republicans (60%) and those who reside in the state’s Central Valley (51%). But it’s opposed by 66% of Democrats, 59% of independents, 65% of San Francisco Bay Area residents, and 54% of Los Angeles residents.

Married likely voters are less likely than the never-married to oppose Prop. 8 (51% vs. 66%).

Prop. 8 is opposed by similar proportions of Latino (54%) and non-Hispanic White (55%) likely voters.

Another interesting finding is that opposition to Prop. 8 doesn’t come exclusively from those who say they generally favor allowing gay and lesbian couples to legally marry. The sample was evenly split on that question — 47% of likely voters favoring marriage equality and 47% opposing it. Thus, consistent with other polls, some respondents who don’t personally support marriage equality nevertheless oppose enacting anti-equality legislation. Indeed, Prop. 8 is supported by only 69% of the likely voters who generally oppose allowing same-sex couples to marry.

Proposition 8 Backers Rationalize The Results

Marriage equality opponents blamed the results on Prop. 8′s official title and summary description, which explicitly frames it as eliminating marriage rights for same-sex couples. As I explained in a previous post, survey research over the years has shown that wording can make a difference. Although “not allowing” something would appear to be equivalent to “forbidding” it, people are generally more reluctant to forbid than to not allow.

Indeed, a July Field Poll that described the ballot measure with the language favored by its supporters (the survey question said Prop. 8 would “provide that only marriage between a man and a woman is valid or recognized in California”) registered slightly less opposition. However, likely voters still rejected it by a margin of 51% to 42%.

Prop. 8 backers tried to find a ray of hope in the PPIC data, noting that amendment supporters were more likely to say the outcome of the vote is “very important” to them — 57% versus 44% of amendment opponents.

Unfortunately for them, the math in this argument is flawed because it doesn’t take into account the fact that there are fewer Prop. 8 supporters than opponents. 57% of the 40% who would vote YES = 23% of respondents saying they support Prop. 8 and the vote is “very important” to them. But 44% of the 54% who would vote NO = 24% of likely voters saying they oppose the amendment and it’s very important.

In other words, about the same number on each side of the issue feel strongly about the initiative. And if we include respondents who said the vote is “somewhat important,” 40% of the sample oppose Prop. 8 and consider the vote important, compared to only 34% who support the initiative and feel it’s important.

Conclusion: Cautious Optimism For Equality Supporters

Not only do the data indicate that Prop. 8 is losing — conventional wisdom holds that ballot measures should have more than 50% support at this stage of the campaign if they’re going to pass — but they may contribute to a widespread expectation that the initiative will go down in flames. Such a perception could affect fundraising (donors often don’t want to throw money at a lost cause) and might create a bandwagon effect (undecided voters may opt to go with the side they believe will win).

Nevertheless, it would be a big mistake for Prop. 8 opponents to be overconfident. The election will be decided by the Californians who actually vote, and Prop. 8 backers are busy mobilizing their base, especially in church congregations. And it’s always possible that events during the next 10 weeks will affect voters’ perceptions in a way that favors Prop. 8.

Noting those caveats, however, the PPIC data are certainly cause for optimism among marriage equality supporters.